How do you assign a value to a global variable in Java?

In Java, global variables are typically defined as member variables within a class. Global variables can be assigned values anywhere within the class, including in constructors, static blocks, and regular methods.

For example, suppose there is a global variable called age.

public class MyClass {
    static int age; // 全局变量

    public static void main(String[] args) {
        MyClass myObj = new MyClass();
        myObj.setAge(20); // 调用方法给全局变量赋值
        System.out.println(age); // 输出：20
    }

    public void setAge(int newAge) {
        age = newAge; // 给全局变量赋值
    }
}

In the example above, the setAge() method is called to assign a value of 20 to the global variable age, and the value of the global variable is printed using System.out.println().

Additionally, if the global variable is a static variable, it can be accessed and assigned directly through the class name, without the need to create an object. For example:

public class MyClass {
    static int age; // 全局静态变量

    public static void main(String[] args) {
        MyClass.age = 20; // 直接给全局静态变量赋值
        System.out.println(MyClass.age); // 输出：20
    }
}

The above are two commonly used methods to assign values to global variables, choose the appropriate method based on your specific needs.